coordinated movement of cytoplasmic and transmembrane domains of ryr1 upon gating协调运动的细胞质和跨膜域ryr1浇注.pdfVIP

PLoS BIOLOGY Coordinated Movement of Cytoplasmic and Transmembrane Domains of RyR1 upon Gating ´ 1* 2 2 1 Montserrat Samso , Wei Feng , Isaac N. Pessah , P. D. Allen 1 Division of Anesthesia Research, Department of Anesthesia, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America, 2 Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America Ryanodine receptor type 1 (RyR1) produces spatially and temporally defined Ca2þ signals in several cell types. How signals received in the cytoplasmic domain are transmitted to the ion gate and how the channel gates are unknown. We used EGTA or neuroactive PCB 95 to stabilize the full closed or open states of RyR1. Single-channel measurements in the presence of FKBP12 indicate that PCB 95 inverts the thermodynamic stability of RyR1 and locks it in a long-lived open state whose unitary current is indistinguishable from the native open state. We analyzed two datasets of 15,625 and 18,527 frozen-hydrated RyR1-FKBP12 particles in the closed and open conformations, respectively, by cryo- ˚ electron microscopy. Their corresponding three-dimensional structures at 10.2 A resolution refine the structure surrounding the ion pathway previously identified in the closed conformation: two right-handed bundles emerging from the putative io